Have You Heard? The protective power of the nose (3:50)

The detection, found through routine milk testing, brings the number of states with infected dairy herds to 21 and follows Washington's first cases in October.

In past cases, the FDA has cited testing that matched the E coli strain that sickened a hospitalized child to unopened Darwin’s dog food and linked the company’s food to a kitten’s death from Salmonella infection. The cases are part of a yearslong record of recalls, illness reports, and disputes over how the agency regulates raw pet food.

The agency says the manufacturer, Arrow Reliance, has not adequately recalled the frozen food, which carries no expiration date and may still be in owners’ freezers.

A severely immunocompromised patient treated in Lyon died in early October. Investigators suspect the patient was bitten by an infected Culicoides midge in a region where the virus circulated in cattle this summer.